An electromagnetic wave phase/amplitude generation device includes a radiation unit configured to radiate electromagnetic waves of a random radiation pattern on a spatial frequency in which a state of the electromagnetic waves to be radiated for each divided region is determined to an imaging object, an imaging unit configured to generate a captured image by imaging scattered electromagnetic waves that are electromagnetic waves generated when the imaging object scatters the electromagnetic waves of the radiation pattern radiated by the radiation unit, and a generation unit configured to generate information indicating at least a phase and amplitude of the electromagnetic waves from the imaging object by performing an arithmetic sparsity constraint operation according to sparsity of the imaging object on the basis of the captured image generated by the imaging unit, information indicating the radiation pattern, and information indicating a signal of the imaging object.