Cooker

A cooker comprising:

• a main body;
• a cavity in the main body forming a cooking chamber in which food is cooked, the cavity comprising a plurality of walls;
• a heater in the cavity providing heat for cooking food inside the cooking chamber;
• a door that opens and closes the cooking chamber;
• a ground coating layer on the plurality of walls, the ground coating layer comprising ceramic components that constitute an enamel coating layer having a first thickness;
• and
• a cover coating layer on an outer surface of the ground coating layer, the cover coating layer comprising phosphorus oxide components having a second thickness,
• wherein the first thickness is thinner than the second thickness,
• wherein the cover coating layer includes 27.1-35.3 wt % P205, 14.6-28.4 wt % Al2O3, 12.8-20.3 wt % ZrO2, 18.7-28.8 wt % mother glass constitution components, and 17.2-25.4 wt % ceramic fillers;
• and
• wherein the ceramic fillers are selected from the group consisting of ZrSiO4, ZrO2.SiO2, eucryptite, and 2MgO.2Al2O3.5SiO2.