A 5-membered cyclic carbonate polysiloxane compound is represented by the below-described formula (1), and is produced by a process that reacts an epoxy-modified polysiloxane compound with carbon dioxide. wherein A means in which R1 means an alkylene group which has from 1 to 12 carbon atoms and may be linked via an element of O, S or N and/or —(C2H4O)b—, R2 means a direct bond or an alkylene group having from 2 to 20 carbon atoms, R2 may be linked to an alicyclic group or aromatic group, b stands for a number of from 1 to 300, and a stands for a number of from 1 to 300.