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 (221a, 221b); a support member which supports the plate member so as to cause the edge parts (221a, 221b) 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 (221a, 221b), 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 (221a, 221b) 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 (221a, 221b); a support member which supports the plate member so as to cause the edge parts (221a, 221b) 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 (221a, 221b), 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 (221a, 221b) 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 (221a, 221b) 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.