A mechanical seal comprising: an annular stationary sealing ring fixed to a fixed side; an annular rotating sealing ring suitable to rotate along with a rotating shaft in a facing manner to the stationary sealing ring to rotate respective sealing faces relative to each other to seal a sealed fluid which exists at an outer side in a radial direction of the respective sealing faces that rotate and slide relative to each other, an outer diameter of the rotating sealing ring being larger than an outer diameter of the stationary sealing ring, the mechanical seal further comprising: a fluid introduction groove provided in a radially outward side of the sealing face of the stationary sealing ring and which is suitable to be exposed to the sealed fluid, and having an opening portion which is opened to the sealed fluid and an end portion which is provided opposite to the opening portion, the end portion of the fluid introduction groove being located between the respective sealing faces, the fluid introduction groove being suitable to supply the sealed fluid from the opening portion to a clearance between the respective sealing faces, characterized by the fluid introduction groove being inclined at an acute angle (θ) to the sealing face of the stationary sealing ring in a direction from the end portion to the opening portion. an annular stationary sealing ring fixed to a fixed side; an annular rotating sealing ring suitable to rotate along with a rotating shaft in a facing manner to the stationary sealing ring to rotate respective sealing faces relative to each other to seal a sealed fluid which exists at an outer side in a radial direction of the respective sealing faces that rotate and slide relative to each other, an outer diameter of the rotating sealing ring being larger than an outer diameter of the stationary sealing ring, the mechanical seal further comprising: a fluid introduction groove provided in a radially outward side of the sealing face of the stationary sealing ring and which is suitable to be exposed to the sealed fluid, and having an opening portion which is opened to the sealed fluid and an end portion which is provided opposite to the opening portion, the end portion of the fluid introduction groove being located between the respective sealing faces, the fluid introduction groove being suitable to supply the sealed fluid from the opening portion to a clearance between the respective sealing faces, characterized by the fluid introduction groove being inclined at an acute angle (θ) to the sealing face of the stationary sealing ring in a direction from the end portion to the opening portion. a fluid introduction groove provided in a radially outward side of the sealing face of the stationary sealing ring and which is suitable to be exposed to the sealed fluid, and having an opening portion which is opened to the sealed fluid and an end portion which is provided opposite to the opening portion, the end portion of the fluid introduction groove being located between the respective sealing faces, the fluid introduction groove being suitable to supply the sealed fluid from the opening portion to a clearance between the respective sealing faces, characterized by the fluid introduction groove being inclined at an acute angle (θ) to the sealing face of the stationary sealing ring in a direction from the end portion to the opening portion.