A radio-frequency heating apparatus includes a radio-frequency power generation unit (120), variable phase shift units (142a to 142d) that change a phase of a radio-frequency power generated by the radio-frequency power generation unit (120), radio-frequency power units (140a to 140d), and a control unit (110) that sets a frequency for the radio-frequency power generation unit (120) and a phase shift amount for the variable phase shift units (142a to 142d). Backward power detection units in the radio-frequency power units (140a to 140d) individually detect a reflected power and a through power at the frequency set for the radio-frequency power generation unit (120) by the control unit (110), and the control unit (110) determines a frequency for the radio-frequency power generation unit (120) and a phase shift amount for the variable phase shift units (142a to 142d) for heating the object, on the basis of the detected amplitude and phase of the reflected wave and the through wave.