To obtain the subject compound useful as an excellent nonionic surfactant and a metal ion absorbing agent.

This 1,3-diketone compound is represented by formula I {RF is 1-20C perfluooroalkyl which may be interrupted by oxygen atom, e.g. (CF2)mF or CF(CF3)O(CF3CF(CF3)O)nC3F7; (m) is 1-15; (n) is an integer of 0-5}. The compound is obtained by reacting a fluoroalkanol peroxide represented by formula II with a (vinyldialkylsilyl)acetic acid alkyl ester to synthesize the corresponding dimer and saponifying the dimer. The compound of formula I is soluble in an aqueous organic solvent such as THF and useful as a nonionic surfactant in order to efficiently lower surface tension of water and can selectively taking calcium ion therein.