A charged particle beam treatment apparatus includes: a cyclotron configured to accelerate charged particles while turning the charged particles along a predetermined orbital plane an irradiation portion configured to irradiate an irradiation object with a charged particle beam while scanning the charged particle beam emitted from the cyclotron a measurement portion configured to measure a dose of the charged particle beam emitted from the cyclotron and a control portion. The cyclotron has a pair of chopper electrodes which can switch ON/OFF of the charged particle beam from the cyclotron by changing an orbit of the charged particles that pass through the orbit, and a power source configured to apply a voltage to the pair of chopper electrodes. The control portion controls a size of a voltage in at least any one of the pair of chopper electrodes based on the dose measured by the measurement portion.
