Package

A package including a mounting surface on which an electronic component is to be mounted, a cavity on the mounting surface, and an attachment surface to which a lid for sealing the cavity is to be attached through an adhesive layer, the package comprising:

• a bottom containing ceramics and having the mounting surface;
• a frame containing ceramics, enclosing the cavity on the bottom outside the mounting surface, and having the attachment surface;
• and
• a wiring part connecting an inside and an outside of the cavity,
• wherein the attachment surface of the frame includes an inner end adjacent to the cavity and an outer end opposite to the inner end in at least one cross-sectional view spanning the inside and the outside of the cavity, the attachment surface having a protruding shape protruding in a thickness direction, at least one of the inner end or the outer end being made lower than a most protruding portion of the protruding shape by 10 μm or more,
• the at least one cross-sectional view includes a first cross-sectional view and a second cross-sectional view,
• in the first cross-sectional view, the most protruding portion has a first height position, and at least one of the inner end or the outer end is made lower than the first height position by 20 μm or more,
• in the second cross-sectional view, the most protruding portion has a second height position, and at least one of the inner end or the outer end is made lower than the second height position by 10 μm or more and less than 20 μm, and
• the second height position in the second cross-sectional view is lower than the first height position in the first cross-sectional view.