PURPOSE: To provide the subject composition containing a specific nonionic surfactant and ethanolamine at a specific ratio, free from residual alkali metal salt, having low frothing tendency and suitable as a detergent for dust-free wear to be used in a semiconductor production room, etc.

CONSTITUTION: The objective composition contains (A) 10-40wt.% of a nonionic surfactant of formula I, II or III (R1 is 8-10C alkyl or alkenyl; R2 and R3 are H, 1-15C alkyl or alkenyl: sum of the carbon numbers of R2 and R3 is 8-22; (n) is integer of 5-30; (m) is integer of 3-20) and (B) 5-30wt.% of ethanolamine and essentially free from a compound containing a salt of an alkali metal such as Na or K and a nonsoap anionic surfactant.