To obtain a new bisphenol compound having excellent oxidative deterioration resistance.

A compound of formula I [A is a 1-6C alkylene; one of two R1 groups is OH or a 1-12C hydroxyalkyl, and the other is H, a 1-4C alkyl or the like; (n) is 0 or 1]. For example, 2, 2'-methylenebis[6-tert- butyl-4-(hydroxymethyl)phenol]. The compound of formula I is obtained, for example, by reacting a phenol compound of formula II with an amine of the formula: HNR2R3 (R2 and R3 are each H, a 1-6C alkyl or the like) (for example, monomethylamine) and an aldehyde of the formula: R4CHO [R4 is a group of the formula: A'H (A' is a 1-5C alkylene)] or a ketone of the formula: (R5)2C=O (R5 is a 1-4C alkyl) to obtain the Mannich base compound of formula III (A' is A), and subsequently reacting the obtained compound of formula III with the compound of formula II in the presence of an alkali catalyst (for example, sodium methoxide).