PURPOSE: To reduce the number of elements to be used, by controlling differential circuits by a common control source in a flip-flop circuit consisting of two bistable circuits which have two differential circuits respectively.

CONSTITUTION: Emitters of transistors TRs Q23 and Q24 of a master flip-flop 13 and TRs Q25 and Q26 of a slave flip-flop 14 are connected commonly and are connected to the collector of a multiemitter TR Q29. Emitters of TRs Q21 and Q22 of the master flip-flop 13 and TRs Q27 and Q28 of the slave flip-flop 14 are connected in common and are connected to collectors of TRs Q30 and Q31, and emitters of TRs Q30 and Q31 are connected to the collector of a TR Q32, which is a current source, together with the emitter of a TR Q29.