A cutting tool which is configured to form a groove in a workpiece, the cutting tool comprising: a plate member which is provided, at a leading end thereof, with edge parts ; a support member which supports the plate member so as to cause the edge parts to be projected; and a fluid supply part which has an ejection port and which is configured to eject, from the ejection port , fluid that can cool the edge parts , wherein: the support member has a non-contact surface which forms a gap with respect to an outer side surface of the plate member ; the gap is opened toward a side where the edge parts are provided; and the ejection port is arranged in the gap , and the ejection port is configured so that the fluid can be ejected toward the plate member , wherein: the fluid supply part has, inside the support member , a flow path through which the fluid passes; and the ejection port is opened in the non-contact surface , and characterized in that the non-contact surface is a notch formed at a leading end surface of the support member, whereby the notch reaches the end surface , which is located in the leading end direction, of the support member and also notches part of the end surface , wherein the plate member is curved so as to be projected toward the support member . a plate member which is provided, at a leading end thereof, with edge parts ; a support member which supports the plate member so as to cause the edge parts to be projected; and a fluid supply part which has an ejection port and which is configured to eject, from the ejection port , fluid that can cool the edge parts , wherein: the support member has a non-contact surface which forms a gap with respect to an outer side surface of the plate member ; the gap is opened toward a side where the edge parts are provided; and the ejection port is arranged in the gap , and the ejection port is configured so that the fluid can be ejected toward the plate member , wherein: the fluid supply part has, inside the support member , a flow path through which the fluid passes; and the ejection port is opened in the non-contact surface , and characterized in that the non-contact surface is a notch formed at a leading end surface of the support member, whereby the notch reaches the end surface , which is located in the leading end direction, of the support member and also notches part of the end surface , wherein the plate member is curved so as to be projected toward the support member . the support member has a non-contact surface which forms a gap with respect to an outer side surface of the plate member ; the gap is opened toward a side where the edge parts are provided; and the ejection port is arranged in the gap , and the ejection port is configured so that the fluid can be ejected toward the plate member , wherein: the fluid supply part has, inside the support member , a flow path through which the fluid passes; and the ejection port is opened in the non-contact surface , and characterized in that the non-contact surface is a notch formed at a leading end surface of the support member, whereby the notch reaches the end surface , which is located in the leading end direction, of the support member and also notches part of the end surface , wherein the plate member is curved so as to be projected toward the support member . the fluid supply part has, inside the support member , a flow path through which the fluid passes; and the ejection port is opened in the non-contact surface , and characterized in that the non-contact surface is a notch formed at a leading end surface of the support member, whereby the notch reaches the end surface , which is located in the leading end direction, of the support member and also notches part of the end surface , wherein the plate member is curved so as to be projected toward the support member . <EOS>