It is an object of the present invention to provide a trehalose compound having high immunopotentiating activity and low toxicity. The compound exhibits a high activating effect on macrophages and neutrophils.The trehalose compound is represented by formula (1), wherein X represents R1-CHR2-, and X' represents R1'-CHR2'-, wherein R1, R1', R2 and R2' independently represent a C1-C21 alkyl group or a hydrogen atom, and wherein n and n' independently represent an integer of 0 to 3.