A photoelectrochemical cell comprising: a semiconductor electrode including a conductor and an n-type semiconductor layer disposed on the conductor; a counter electrode connected electrically to the conductor; an electrolyte in contact with surfaces of the n-type semiconductor layer and the counter electrode; and a container accommodating the semiconductor electrode, the counter electrode and the electrolyte, wherein the photoelectrochemical cell generates hydrogen by irradiation of the n-type semiconductor layer with light, and relative to a vacuum level, (i) band edge levels of a conduction band (E CN) and a valence band (E VN) in a surface near-field region (122-N) of the n-type semiconductor layer, are equal to or higher than band edge levels of a conduction band (E C1) and a valence band (E V1) in a junction plane near-field region, respectively, wherein the surface near-field region (122-N) is the region of the surface of the n-type semiconductor layer that faces a light incident portion of the cell and the junction plane near-field region is the region of the junction plane of the n-type semiconductor layer with the conductor, (ii) a Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor is higher than a Fermi level of the surface near-field region (E FN) of the n-type semiconductor layer, and (iii) a Fermi level of the conductor (E FC) is higher than the Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor. a semiconductor electrode including a conductor and an n-type semiconductor layer disposed on the conductor; a counter electrode connected electrically to the conductor; an electrolyte in contact with surfaces of the n-type semiconductor layer and the counter electrode; and a container accommodating the semiconductor electrode, the counter electrode and the electrolyte, wherein the photoelectrochemical cell generates hydrogen by irradiation of the n-type semiconductor layer with light, and relative to a vacuum level, (i) band edge levels of a conduction band (E CN) and a valence band (E VN) in a surface near-field region (122-N) of the n-type semiconductor layer, are equal to or higher than band edge levels of a conduction band (E C1) and a valence band (E V1) in a junction plane near-field region, respectively, wherein the surface near-field region (122-N) is the region of the surface of the n-type semiconductor layer that faces a light incident portion of the cell and the junction plane near-field region is the region of the junction plane of the n-type semiconductor layer with the conductor, (ii) a Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor is higher than a Fermi level of the surface near-field region (E FN) of the n-type semiconductor layer, and (iii) a Fermi level of the conductor (E FC) is higher than the Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor. (i) band edge levels of a conduction band (E CN) and a valence band (E VN) in a surface near-field region (122-N) of the n-type semiconductor layer, are equal to or higher than band edge levels of a conduction band (E C1) and a valence band (E V1) in a junction plane near-field region, respectively, wherein the surface near-field region (122-N) is the region of the surface of the n-type semiconductor layer that faces a light incident portion of the cell and the junction plane near-field region is the region of the junction plane of the n-type semiconductor layer with the conductor, (ii) a Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor is higher than a Fermi level of the surface near-field region (E FN) of the n-type semiconductor layer, and (iii) a Fermi level of the conductor (E FC) is higher than the Fermi level of the junction plane near-field region (E F1) of the n-type semiconductor layer with the conductor.