In order to secure printing quality, provided is a head unit (10) including: a thermal head (9), including a heating body (15) formed on one surface of a glass substrate made of a transparent glass material, the heating body being configured to generate heat when supplied with external power; and a support body (11) which is laminated onto the glass substrate in a stacked state, in which the glass substrate and the support body (11) include a plurality of lamination reference marks (21) and a plurality of head positioning reference marks (23), respectively, which are disposed so as to be mutually aligned in a direction along the one surface of the glass substrate.