Provided is a start control device capable of reducing power consumption during the driving operation of a starter motor, to thereby improve fuel efficiency of a vehicle. In the start control device, a motor drive torque estimating part (123) estimates a motor drive torque based on a battery voltage drop amount of a battery (107) that supplies an electric power to a motor (105). A start control part (122) turns off energization of a pinion pushing device (104) by a pinion driving part (120) when the motor drive torque estimated by the motor drive torque estimating part (123) is equal to or larger than a given value.