A robot control device that controls operation of a robot having an actuator includes a casing, an actuator driver, a drive-control board, a main control board, a main power supply board, a vent passage, a cooling fan, and a holding member. The actuator driver is accommodated in the casing and drives the actuator. The drive-control board is accommodated in the casing and controls operation of the actuator driver. The main control board is accommodated in the casing and controls operation of the drive-control board. The main power supply board is accommodated in the casing and supplies a power to the drive-control board and the main control board. The vent passage is defined by at least the drive-control board, the main control board, and the main power supply board and has an end open to the exterior of the casing. The cooling fan is arranged at an end of the vent passage and causes the air to flow through the vent passage. The holding member is provided in the vent passage and holds the actuator driver.