To provide voltage detection techniques for determining whether a voltage effective value, a peak voltage value, and a quasi-peak voltage value of an AC power supply voltage are high or low in an image heating device having a heater capable of changing over resistance values, and an AD/DC converter capable of changing over between voltage doubler rectification and full-wave rectification.

This voltage detection device includes first and second voltage detection circuits which detect the voltage effective value of an AC power supply 201 for supplying a first commercial voltage and a second commercial voltage, which is lower than the first commercial voltage. This voltage detection device further includes a control means 203 which is adapted to determine that the voltage waveform of the AC power supply is a voltage waveform of the voltage effective value of the first commercial voltage, when the first detection circuit 301 detects that a ratio of a time when the voltage of the AC power supply becoming a first threshold voltage or more is a first threshold ratio or more, or when the second voltage detection circuit 301 detects that a ratio of a time when the voltage of the AC poser supply becoming a second threshold voltage or more, which is lower than the first threshold voltage, is a second threshold ratio or more, which is higher than the first threshold ratio.