A shot-treatment apparatus (10, 110) comprising: a projecting device for projecting shot with compressed air through a nozzle against a workpiece; a rotatable main table located in a place where both a projection area to be projected upon by the shot from the projecting device and a non-projection area other than the projection area are included; a plurality of rotatable satellite tables mounted on the main table, wherein each of the satellite tables for placing workpieces has a driven shaft in parallel with a main shaft of the main table; a holding assembly disposed above the projection area of the main table, wherein the holding assembly holds down the workpiece placed on the satellite table with a holding member which is configured to be rotatable along with the workpiece, wherein the shot-treatment apparatus (10, 110) further comprises: a plurality of first mating members disposed on the individual driven shafts extending downward from each of the satellite tables; at least one second mating member located below the main table in the projection area, wherein the second mating member is engageable with any of the first mating members to transmit a rotational driving force to the first mating member; characterised by a meshing assembly for engaging the second mating member with the first mating member when the rotation of the main table is suspended, and for disengaging the second mating member from the first mating member before starting the rotation of the main table, and wherein, when the workpiece is rotated about the driven shaft of the satellite table, the holding member is allowed to rotate along with the workpiece. a projecting device for projecting shot with compressed air through a nozzle against a workpiece; a rotatable main table located in a place where both a projection area to be projected upon by the shot from the projecting device and a non-projection area other than the projection area are included; a plurality of rotatable satellite tables mounted on the main table, wherein each of the satellite tables for placing workpieces has a driven shaft in parallel with a main shaft of the main table; a holding assembly disposed above the projection area of the main table, wherein the holding assembly holds down the workpiece placed on the satellite table with a holding member which is configured to be rotatable along with the workpiece, wherein the shot-treatment apparatus (10, 110) further comprises: a plurality of first mating members disposed on the individual driven shafts extending downward from each of the satellite tables; at least one second mating member located below the main table in the projection area, wherein the second mating member is engageable with any of the first mating members to transmit a rotational driving force to the first mating member; characterised by a meshing assembly for engaging the second mating member with the first mating member when the rotation of the main table is suspended, and for disengaging the second mating member from the first mating member before starting the rotation of the main table, and wherein, when the workpiece is rotated about the driven shaft of the satellite table, the holding member is allowed to rotate along with the workpiece. a plurality of first mating members disposed on the individual driven shafts extending downward from each of the satellite tables; at least one second mating member located below the main table in the projection area, wherein the second mating member is engageable with any of the first mating members to transmit a rotational driving force to the first mating member; characterised by a meshing assembly for engaging the second mating member with the first mating member when the rotation of the main table is suspended, and for disengaging the second mating member from the first mating member before starting the rotation of the main table, and wherein, when the workpiece is rotated about the driven shaft of the satellite table, the holding member is allowed to rotate along with the workpiece.