MRI signal data is received individually by multiple element coils. For each channel assigned to each element coil at a positioning image taking time, the collected magnetic resonance signal data is entered into a storage unit. An image is reconstructed from the magnetic resonance signal data stored in the storage unit, by referring the storage unit regarding the channel selected at the positioning image taking time. The reconstructed image is displayed. When a channel selection change command is received, an image is reconstructed using the magnetic resonance signal data stored in the storage unit, by referring to the storage unit regarding the changed channel. The after-change corrected image is displayed.