An image processing apparatus, having a reconstruction circuit for which reconstruction based on construction data is possible, comprises a first storage unit configured to store the construction data; a writing unit configured to, when the image processing apparatus transitions to a power saving state, write the construction data, which is stored in a first storage unit, in a second storage unit which is different to the first storage unit; and a reconstruction unit configured to, when the image processing apparatus returns from the power saving state, reconstruct the reconstruction circuit based on the construction data stored in the second storage unit.