In a ceramic heater having a plate-like body made of a ceramic, heating element in one main face of the plate like body, and an electric supply portion to be electrically connected with the heating element, it has been a problem that the temperature is uneven if bent portions are formed in heat generating patterns. The ceramic heater simultaneously satisfying the following: 0.15<=S<=0.85, 0.3<=P<=6.71XS<2>+1.52, and 0.3<=G<=6.71x(1-S)<2>+1.55, in which the reference character S1 denotes the surface area of the heating element in optional 10 mm square region of the effective heat generation area having the heating element therein; the surface ratio S denotes S=S1 / 100 mm<2>, the reference character P denotes the width of the heating element: and the reference character G denotes the gap between the heating element.