A speed control device includes: a vehicle information output unit that outputs at least two, as vehicle information, of measurement information on forward/backward acceleration of a vehicle measured by an acceleration sensor, forward/backward actual acceleration of the vehicle obtained from an output rotation of an automatic transmission, and a traveling driving force based on a driving force output by a driving source and an air resistance acting on the vehicle; and a setting unit that selects a shift mode by comparing the vehicle information with a predetermined selection threshold and sets a shift point for controlling the automatic transmission provided in the vehicle based on the shift mode.