A distance measurement device includes a light emitting unit; a light receiving unit; a distance calculation unit that calculates a distance to an object; and a controller that controls the light emitting unit and the light receiving unit to determine whether or not there is interference from another distance measurement device, from a distance calculation result from the distance calculation unit. The controller includes a light emission and exposure period-setting unit that sets a light emission and exposure period of the light emitting unit and the light receiving unit, a distance variation measurement unit that measures a variation of distance values repeatedly obtained in a predetermined duration by the distance calculation unit, and an interference determination unit that compares a distance variation value to a threshold value which is determined in advance, to determine whether or not there is interference.