A board-to-board connector has such a configuration that at least one a first reinforcing bracket of a first connector and a second reinforcing bracket of a second connector is provided with a bent portion having a crank shape, viewed from the insertion/removal direction of the first and second connectors. Owing to such a configuration, deformation of the first reinforcing bracket and/or the second reinforcing bracket can be prevented, and a firm engagement state between the first and second reinforcing brackets is achieved. As a result, a strong removal force is required for releasing the engagement state, and a stable engagement between the first connector and the second connector can be maintained.