A heating cooker comprising: a top plate on which a cooking container to be heated is placed; an outer case having an upper surface on which the top plate is placed and making up a main body; a heater element heating the cooking container to be heated on the top plate; and a light emitting device disposed in the outer case, for displaying e.g. the state of heating effected by the heater element, wherein the top plate comprising: a glass substrate in the form of a transparent light-transmitting low-expansion crystallized glass made mainly of Li 2 O-AL 2 O 3 -SiO 2 and having β-quartz solid solution as a main crystal, whose crystal size is smaller than the wavelength of visible light; a design layer having a black-based color disposed on an undersurface of the glass substrate; a diffusion region disposed partially on an undersurface of the design layer, for diffusedly emitting light from the light emitting device, the diffusion region containing a pearl pigment comprised of an inorganic pigment coated with a metal oxide; and a light-blocking layer disposed on the undersurface of the design layer at least at a portion other than the diffusion region, for blocking light from below, the light-blocking layer containing an inorganic pigment. a top plate on which a cooking container to be heated is placed; an outer case having an upper surface on which the top plate is placed and making up a main body; a heater element heating the cooking container to be heated on the top plate; and a light emitting device disposed in the outer case, for displaying e.g. the state of heating effected by the heater element, wherein the top plate comprising: a glass substrate in the form of a transparent light-transmitting low-expansion crystallized glass made mainly of Li 2 O-AL 2 O 3 -SiO 2 and having β-quartz solid solution as a main crystal, whose crystal size is smaller than the wavelength of visible light; a design layer having a black-based color disposed on an undersurface of the glass substrate; a diffusion region disposed partially on an undersurface of the design layer, for diffusedly emitting light from the light emitting device, the diffusion region containing a pearl pigment comprised of an inorganic pigment coated with a metal oxide; and a light-blocking layer disposed on the undersurface of the design layer at least at a portion other than the diffusion region, for blocking light from below, the light-blocking layer containing an inorganic pigment. a glass substrate in the form of a transparent light-transmitting low-expansion crystallized glass made mainly of Li 2 O-AL 2 O 3 -SiO 2 and having β-quartz solid solution as a main crystal, whose crystal size is smaller than the wavelength of visible light; a design layer having a black-based color disposed on an undersurface of the glass substrate; a diffusion region disposed partially on an undersurface of the design layer, for diffusedly emitting light from the light emitting device, the diffusion region containing a pearl pigment comprised of an inorganic pigment coated with a metal oxide; and a light-blocking layer disposed on the undersurface of the design layer at least at a portion other than the diffusion region, for blocking light from below, the light-blocking layer containing an inorganic pigment.