An object of the present invention is to provide a dithioester compound capable of generating an alkoxy radical having high hydrogen abstraction ability. The present invention provides a dithioester compound represented by a formula (1). The dithioester compound according to the present invention is capable of generating an alkoxy radical (R1R2R3CO.) having high hydrogen abstraction ability. Thus, the dithioester compound according to the present invention can be suitably used as an additive (RAFT agent) when synthesizing a polymer material having a crosslinked structure. [In the formula (1), R1 to R3 each independently represent an alkyl group having 1 or more carbon atoms, an alkenyl group having two or more carbon atoms, an alkynyl group having two or more carbon atoms, a hydrogen atom, or a halogen atom.]