There is provided a power supply device for a work unit that supplies power to multiple work units constituting a work device as power supply targets, the device including: a first power supply line through which power supply is stopped when an emergency stop condition is satisfied and a second power supply line through which power supply is not stopped even when the emergency stop condition is satisfied, in which the first power supply line and the second power supply line can be used individually according to a difference in a safety structure of each work unit. According to this, when the emergency stop condition is satisfied, it is possible to reduce the restoration time required when the emergency stop is eliminated while guaranteeing the safety of the entire work device configured by the multiple work units.