A mobile capsule device 10 comprises a long capsule body 11 having a permanent magnet 13 movable in the lengthwise direction with respect to the long capsule body and a coil for driving the permanent magnet 13, while a propulsion force is generated entirely by applying an alternate current to the coil and performing back and forth movements of the permanent magnet 13. The coil has first and second coil parts 15 and 16 arranged circumferentially in front and back of the permanent magnet 13, and a frequency of an alternate current applied to the first and second coil parts 15 and 16 is made to accord with a resonance frequency of the capsule device 10 generated by a back and forth vibration of the permanent magnet 13. Thereby, a self-propelled, mobile capsule device 10 which is downsized, compact and efficient and a control method thereof can be provided.