To provide structure of a screwless terminal part of a circuit breaker, which is hard to cause an error of an attachment position of a connection electric wire releasing tool of a screwless terminal with an identification property for each pole as much as possible in assembly of the circuit breaker.

Structure of a screwless terminal part 100 with connection electric wire releasing tools 30, 31 in a circuit breaker formed by arranging wall parts of cases A-C partitioning electric wire connection terminals of the respective poles of the circuit breaker in parallel with each other in a parallel arrangement direction of the electric wire connection terminals is constituted by being provided with attachment prevention means of the connection electric wire releasing tool 31 for other pole for preventing that the connection electric wire releasing tool 31 for other pole is attached to a self-pole to the electric wire connection terminal part of the self-pole.