Provided are: a (hydrolyzable) organosiloxane compound which is represented by general formula (1) and contains a lipophilic group capable of forming a cured film having excellent lipophilicity and wear resistance; and a surface treatment agent containing the compound.




(In the formula, A is any one among —CH3, —C(═O)OR1, —C(═O)NR12, —C(═O)SR1, and —P(═O)(OR1)2; R1 is a hydrogen atom, a C1-30 alkyl group, a C6-30 aryl group, or a C7-30 aralkyl group; Y is independently a divalent organic group; W is independently a C1-4 alkyl group, a phenyl group, a hydroxyl group, or a hydrolyzable group; R is independently a C1-4 alkyl group or a phenyl group; X is independently a hydroxyl group or a hydrolyzable group; n is an integer of 1-3; and q is an integer of 1-3.)