PURPOSE: To provide a nonionic surfactant containing a specific polyoxyalkylene glycerol ether, having low frothing tendency and sufficiently high cleaning power and penetration power and usable as a detergent, etc., without causing the contamination of a cleaning machine and the cleaning object and the pollution of river by waste water.

CONSTITUTION: Epichlorohydrin is made to react with an alcohol (e.g. polyoxyethylene lauryl ether) in an autoclave made of stainless steel in the presence of SnCl4, etc., as an etherifying catalyst to obtain an alkylglycerol chlorohydrin. The compound is made to react with an alcohol component in the presence of NaOH and the obtained bis-alkylglyceryl ether is reacted with ethylene oxide or propylene oxide to obtain the objective low-frothing nonionic surfactant composition expressed by formula [A is C2H4 or CH2C(CH3)H; R1 and R2 are 1-20C alkyl; x+y+z is 0-100]. The surfactant composition has strong cleaning power and penetration power and is usable without causing the contamination of a cleaning machine and the cleaning object and the pollution of river by the foaming of waste water.