An abrasive nozzle head comprising, a hollow head body that is mounted to a nozzle adapter supplying high pressure water, the interior of the head body including: a water nozzle that jets high pressure water; a mixing chamber where a abrasive is mixed into a water jet from the water nozzle; and an abrasive nozzle that discharges an abrasive water jet from the mixing chamber, the water nozzle, mixing chamber, and abrasive nozzle being arranged coaxially with the nozzle adapter, the abrasive nozzle head being provided with a abrasive supply portion that supplies the abrasive to the mixing chamber through the head body, wherein the head body has a recessed hole formed by drilling from a side surface of the head body, the recessed hole intersecting with a jet axis of the water jet, and wherein the abrasive nozzle head includes: a mixer member that is removably inserted into the recessed hole from outside the head body, and formed with the mixing chamber and a abrasive supply port introducing the abrasive into the mixing chamber; a positioning portion that positions the mixing chamber coaxially with the water nozzle and the abrasive nozzle when the mixer member is fully inserted; and a fixing portion that releasably fixes the fully inserted position of the mixer member, characterized in that, the positioning portion comprises fitting portions that are formed on an outer peripheral portion of the mixer member and around an opening of the recessed hole and shaped to fit each other, and with the fitting portions fitted together, the mixing chamber is positioned coaxially with the water nozzle and the abrasive nozzle, thereby providing the fully inserted position of the mixer member. a hollow head body that is mounted to a nozzle adapter supplying high pressure water, the interior of the head body including: a water nozzle that jets high pressure water; a mixing chamber where a abrasive is mixed into a water jet from the water nozzle; and an abrasive nozzle that discharges an abrasive water jet from the mixing chamber, the water nozzle, mixing chamber, and abrasive nozzle being arranged coaxially with the nozzle adapter, the abrasive nozzle head being provided with a abrasive supply portion that supplies the abrasive to the mixing chamber through the head body, a water nozzle that jets high pressure water; a mixing chamber where a abrasive is mixed into a water jet from the water nozzle; and an abrasive nozzle that discharges an abrasive water jet from the mixing chamber, the water nozzle, mixing chamber, and abrasive nozzle being arranged coaxially with the nozzle adapter, the abrasive nozzle head being provided with a abrasive supply portion that supplies the abrasive to the mixing chamber through the head body, wherein the head body has a recessed hole formed by drilling from a side surface of the head body, the recessed hole intersecting with a jet axis of the water jet, and wherein the abrasive nozzle head includes: a mixer member that is removably inserted into the recessed hole from outside the head body, and formed with the mixing chamber and a abrasive supply port introducing the abrasive into the mixing chamber; a positioning portion that positions the mixing chamber coaxially with the water nozzle and the abrasive nozzle when the mixer member is fully inserted; and a fixing portion that releasably fixes the fully inserted position of the mixer member, characterized in that, a mixer member that is removably inserted into the recessed hole from outside the head body, and formed with the mixing chamber and a abrasive supply port introducing the abrasive into the mixing chamber; a positioning portion that positions the mixing chamber coaxially with the water nozzle and the abrasive nozzle when the mixer member is fully inserted; and a fixing portion that releasably fixes the fully inserted position of the mixer member, characterized in that, the positioning portion comprises fitting portions that are formed on an outer peripheral portion of the mixer member and around an opening of the recessed hole and shaped to fit each other, and with the fitting portions fitted together, the mixing chamber is positioned coaxially with the water nozzle and the abrasive nozzle, thereby providing the fully inserted position of the mixer member.