A propeller fan comprising: a plurality of blades circumferentially spaced from each other for performing blowing according to rotation; a connection portion connecting base portions of the plurality of neighboring blades; a rotation shaft arranged coaxially to a rotation center of said blades, protruding from the intake side of said connection portion, and having an end surface parallel to a plane perpendicular to a direction of a rotation axis of said blades, when the propeller fan is viewed in the direction of the rotation axis and an imaginary circle is drawn to separate said plurality of blades from each other in the circumferential direction, said connection portion being defined inside said imaginary circle, and said plurality of blades are defined outside said imaginary circle, said connection portion being coaxial to the rotation axis of said blades, extending between one blade among said plurality of blades and the different blade neighboring to said one blade, being formed in a region connecting said base portions of said one and different blades together, extending radially outward from the rotation axis of said blades, and having a blade-surface-like surface for performing blowing according to rotation, and a minimum distance from the rotation axis to an outer periphery of said connection portion on a line perpendicularly crossing the rotation axis being longer than a distance from the rotation axis to the outer periphery of said rotation shaft on said line, when the propeller fan is viewed in the direction of the rotation axis of said blades; and a flat surface portion arranged on the outlet side of said connection portion, having an outer diameter larger than an outer diameter of said rotation shaft when projected in a direction of the rotation axis of said blades and having a flat surface parallel to said end surface, characterised by an annular protrusion protruding from the outlet side of said connection portion and arranged coaxially to a rotation center of said blades, said annular protrusion having an inner diameter larger than the outer diameter of said rotation shaft when projected in the direction of the rotation axis of said blades. a plurality of blades circumferentially spaced from each other for performing blowing according to rotation; a connection portion connecting base portions of the plurality of neighboring blades; a rotation shaft arranged coaxially to a rotation center of said blades, protruding from the intake side of said connection portion, and having an end surface parallel to a plane perpendicular to a direction of a rotation axis of said blades, when the propeller fan is viewed in the direction of the rotation axis and an imaginary circle is drawn to separate said plurality of blades from each other in the circumferential direction, said connection portion being defined inside said imaginary circle, and said plurality of blades are defined outside said imaginary circle, said connection portion being coaxial to the rotation axis of said blades, extending between one blade among said plurality of blades and the different blade neighboring to said one blade, being formed in a region connecting said base portions of said one and different blades together, extending radially outward from the rotation axis of said blades, and having a blade-surface-like surface for performing blowing according to rotation, and a minimum distance from the rotation axis to an outer periphery of said connection portion on a line perpendicularly crossing the rotation axis being longer than a distance from the rotation axis to the outer periphery of said rotation shaft on said line, when the propeller fan is viewed in the direction of the rotation axis of said blades; and a flat surface portion arranged on the outlet side of said connection portion, having an outer diameter larger than an outer diameter of said rotation shaft when projected in a direction of the rotation axis of said blades and having a flat surface parallel to said end surface, characterised by an annular protrusion protruding from the outlet side of said connection portion and arranged coaxially to a rotation center of said blades, said annular protrusion having an inner diameter larger than the outer diameter of said rotation shaft when projected in the direction of the rotation axis of said blades.