A trisphenol compound is expressed by formula (1), wherein R represents an alkyl group or alkoxyl group with 1 to 8 carbon atoms, phenyl group or hydroxyl group; R1 represents an alkyl group or alkoxyl group with 1 to 8 carbon atoms, or phenyl group; R2 represents an alkyl group or alkoxyl group with 1 to 8 carbon atoms; R3 represents a hydrogen atom or alkyl group with 1 to 8 carbon atoms; a represents 0, 1, 2, or 3; b represents 1 or 2; and c and d represent 0, 1, 2, 3, or 4; where the sum of b and c is 5 or less; R's may be either the same or different when a is 2 or more; R1's may be either the same or different when c is 2 or more; and R2's may be either the same or different when d is 2 or more.