To highly accurately predict remaining machining time required for cutting, a controller of a machining time prediction device includes a storage in which a machining program is stored, a simulator that performs a simulation in which a cutting machine cuts a workpiece in accordance with the machining program to generate a control pattern in which control information of a spindle and a holder is recorded, a machining time calculator that generates, based on the control pattern, a machining time table in which remaining machining time for each step of the machining program, a machining time acquirer that acquires a step of the machining program cutting of which is performed by the cutting machine at a current time point and acquires the remaining machining time for the step of the machining program, which has been acquired, from the machining time table, and a display controller that displays the remaining machining time that has been acquired by the machining time acquirer on a display screen.