从学术角度讲，纯水又名高纯水，是指化学纯度极高的水，其主要应用在生物、 化学化工、冶金、宇航、电力等领域，但其对水质纯度要求相当高，所以一般应用最普遍的还是电子工业。例如电力系统所用的纯水，要求各杂质含量低达到“微克/升”级。
Academically speaking, pure water, also known as high-purity water, refers to water with extremely high chemical purity. It is mainly used in biology, chemical industry, metallurgy, aerospace, power and other fields. However, its requirement for water purity is quite high, so the most common application is the electronic industry. For example, the pure water used in power system requires that the impurity content should be as low as "microgram/liter".
在纯水的制作中，水质标准所规定的各项指标应该根据电子(微电子)元器件(或材料)的生产工艺而定(如普遍认为造成电路性能破坏的颗粒物质的尺寸为其线宽的1/5-1/10)，但由于微电子技术的复杂性和影响产品质量的因素繁多，至今尚无一份由工艺试验得到的适用于某种电路生产的完整的水质标准。电子级水标准也在不断地修订，而且高纯水分析领域的许多突破和发展，新的仪器和新分析方法的不断应用都为制水工艺的发展创造了条件。
In the manufacture of pure water, the specifications specified in the water quality standard should be determined according to the production process of electronic (microelectronic) components (or materials). For example, it is generally believed that the size of particulate matter causing circuit performance damage is 1/5-1/10 of its linewidth. However, due to the complexity of microelectronic technology and the various factors affecting product quality, there is no one suitable for the production process test. Complete water quality standards for certain circuit production. Electronic water standards are also constantly revised, and many breakthroughs and developments in the field of high purity water analysis. The continuous application of new instruments and new analytical methods has created conditions for the development of water processing technology.
在高纯水的国家标准为：GB1146.1-89至GB1146.11-89[168]，目前我国高纯水的标准将电子级水分为五个级别：Ⅰ级、Ⅱ级、Ⅲ级、Ⅳ级和Ⅴ级，该标准是参照ASTM电子级标准而制定的。
The national standard of high purity water is GB1146.1-89 to GB1146.11-89 [168]. At present, the standard of high purity water in our country will be divided into five grades: grade I, grade II, grade III, grade IV and grade V. The standard is formulated according to ASTM electronic standard.
高纯水的水质标准中所规定的各项指标的主要依据有：1.微电子工艺对水质的要求；2.制水工艺的水平；3.检测技术的现状。
The main basis of the indicators stipulated in the water quality standard of high purity water are as follows: 1. Requirements of microelectronic technology for water quality; 2. Level of water production technology; 3. Current status of detection technology.
高纯水的生产过程中，水中的阴、阳离子可用电渗析法、反渗透法及离子交换树脂技术等去除
In the production of high purity water, anions and cations can be removed by electrodialysis, reverse osmosis and ion exchange resin.
水中的颗粒一般可用超过滤、膜过滤等技术去除
Particles in water can be removed by ultrafiltration and membrane filtration.
水中的细菌，目前国内多采用加药或紫外灯照射或臭氧杀菌的方法去除
Bacteria in water are mostly removed by adding medicine or ultraviolet lamp irradiation or ozone sterilization in China at present.
水中的TOC则一般用活性炭、反渗透处理。
TOC in water is generally treated with activated carbon and reverse osmosis.
在高纯水应用的领域中，水的纯度直接关系到器件的性能、可靠性、阈值电压，导致低击穿，产生缺陷，还影响材料的少子寿命，因此高纯水要求具有相当高的纯度和精度。
In the field of application of high purity water, the purity of water is directly related to the performance, reliability and threshold voltage of the device, resulting in low breakdown, defects, and minority carrier lifetime of the material. Therefore, high purity water requires considerable purity and accuracy.
高纯水不能作为饮用水的原因主要是，天然水中溶解的气体主要有O2、CO2、SO2和少量的CH4、氡气、氯气等，在高纯水的生产过程中，还必需去除这类的气体。为了有效的去除杂质，在生产高纯水的过程中，加入了一些化学杀菌剂，如甲醛、双氧水、次氯酸钠等。
The main reason why high-purity water can not be used as drinking water is that the dissolved gases in natural water are mainly O2, CO2, SO2 and a small amount of CH4, radon, chlorine, etc. In the production process of high-purity water, it is necessary to remove such gases. In order to remove impurities effectively, some chemical fungicides such as formaldehyde, hydrogen peroxide and sodium hypochlorite were added in the process of producing high purity water.