An injection molding machine has a clamp that generates electromagnetic force and that secures a moving plate or a fixed plate using attractive force that is produced by the electromagnetic force; and a controller that controls separation force that acts on the moving plate or the fixed plate such that the separation force is less than the attractive force.

An injection molding machine has a clamp that generates electromagnetic force and that secures a moving plate or a fixed plate using attractive force that is produced by the electromagnetic force; a pressure sensor that is provided in the clamp, wherein the pressure sensor measures contact pressure that acts between the moving plate or the fixed plate and the clamp; and a controller for performing a measure to prevent detachment of the moving plate or the fixed plate based on the contact pressure.