A highly volatile electrical/electronic parts surfactant containing a polyether-modified silicone having one polyether chain in the molecule, wherein the surface tension at 25.degree. C. of a 0.01 mass % aqueous solution thereof is 25 mN/m or less, the aforesaid silicone is expressed by the following average structural formula (1), and when heated from room temperature to 200.degree. C. at a rate of 5.degree. C./minute to 200.degree. C. and maintained at a temperature of 200.degree. C. for 100 minutes, the polyether-modified silicone completely volatilizes without leaving any remainder, and a method of manufacturing this highly volatile polyether-modified silicone are disclosed. AMe.sub.2SiO(MeASiO).sub.nSiMe.sub.2A (1)In formula (1), any one of A is a substituent group expressed by the following general formula (2), the remaining A are methyl groups and n is an integer from 0-2. --C.sub.aH.sub.2aO(C.sub.2H.sub.4O).sub.bR (2)In formula (2), a is 3-4, b is an integer from 1-7 and R is a methyl group or an ethyl group.