A tape expanding apparatus for expanding an expandable tape of a frame unit in which a workpiece is supported through the expandable tape to an annular frame includes a frame holding unit for holding the annular frame, a chuck table surrounded by the frame holding unit and having a holding surface for holding the workpiece through the expandable tape, and a position adjusting unit for adjusting a position of the workpiece with respect to the holding surface. The position adjusting unit includes a position detecting unit for detecting the position of the workpiece held on the holding surface and a position control unit having an abutting unit adapted to abut against an outer circumference of the annular frame supported by the frame holding unit and a moving mechanism for moving the abutting unit according to the position of the workpiece detected by the position detecting unit.