A processing apparatus includes a chuck table for sucking and holding a workpiece and a camera unit imaging the workpiece. The chuck table includes a light passing portion that passes light. The light passing portion includes a first region that overlaps with the workpiece and has a first mirror face that reflects light that advances from the first region into the light passing portion. The camera unit can image the workpiece by detecting light reflected by the first mirror face after having been reflected by the workpiece held by the chuck table and advanced into the light passing portion.