A light emitting substrate comprising: a phosphor substrate; and at least one light emitting element mounted on a front face of the phosphor substrate and being formed as a chip sized package, CSP, and comprising a light emitting diode, LED covered with a phosphor sealing layer comprising a first phosphor, the phosphor substrate comprising: an insulating substrate; an electrode layer disposed on a front face of the insulating substrate comprising a bonded portion bonded to the light emitting element; and a phosphor layer which is disposed on the front face of the insulating substrate to form the front face of the phosphor substrate and includes a second phosphor in which a light emission peak wavelength, in a case where light emitted by the light emitting element is used as excitation light, is in a visible light region, wherein a surface (34A1, 34B1) of the electrode layer facing an outer side in a thickness direction of the insulating substrate is a flat surface, and at least a part of the phosphor layer is disposed on the front surface of the electrode layer other than and around the bonded portion bonded to the light emitting element, and the region of the front face of the insulating substrate where the phosphor layer is disposed is a region that is equal to or more than 80% of the front face of the insulating substrate. a phosphor substrate; and at least one light emitting element mounted on a front face of the phosphor substrate and being formed as a chip sized package, CSP, and comprising a light emitting diode, LED covered with a phosphor sealing layer comprising a first phosphor, the phosphor substrate comprising: an insulating substrate; an electrode layer disposed on a front face of the insulating substrate comprising a bonded portion bonded to the light emitting element; and a phosphor layer which is disposed on the front face of the insulating substrate to form the front face of the phosphor substrate and includes a second phosphor in which a light emission peak wavelength, in a case where light emitted by the light emitting element is used as excitation light, is in a visible light region, wherein a surface (34A1, 34B1) of the electrode layer facing an outer side in a thickness direction of the insulating substrate is a flat surface, and at least a part of the phosphor layer is disposed on the front surface of the electrode layer other than and around the bonded portion bonded to the light emitting element, and the region of the front face of the insulating substrate where the phosphor layer is disposed is a region that is equal to or more than 80% of the front face of the insulating substrate. an insulating substrate; an electrode layer disposed on a front face of the insulating substrate comprising a bonded portion bonded to the light emitting element; and a phosphor layer which is disposed on the front face of the insulating substrate to form the front face of the phosphor substrate and includes a second phosphor in which a light emission peak wavelength, in a case where light emitted by the light emitting element is used as excitation light, is in a visible light region, wherein a surface (34A1, 34B1) of the electrode layer facing an outer side in a thickness direction of the insulating substrate is a flat surface, and at least a part of the phosphor layer is disposed on the front surface of the electrode layer other than and around the bonded portion bonded to the light emitting element, and the region of the front face of the insulating substrate where the phosphor layer is disposed is a region that is equal to or more than 80% of the front face of the insulating substrate.