A stirring processing apparatus comprising: a stirring blade configured to rotate at a high speed and a stirring chamber provided with a screen enclosing the stirring blade, configured to perform, under a state in which the stirring chamber is disposed in a fluid to be processed, a process of applying a shear force to the fluid by rotating at least either one of the screen and the stirring blade thereby effecting a relative rotation between the screen and the stirring blade; the stirring chamber having a suction opening to suck the fluid from outside to inside and an ejecting opening to eject the fluid from inside to outside by the relative rotation, these openings being disposed at different axial positions along the axis of the relative rotation; characterized by a suppressing body connected to an outer wall of the stirring chamber between its suction opening and its ejecting opening, and extending outwardly from the stirring chamber so as to divide a suction flow, which is a flow of the fluid from outside into the suction opening, from an ejecting flow, which is a flow of the fluid ejected from the ejecting opening to the outside, thereby suppressing fluid interference outside the stirring chamber between the suction flow and the ejecting flow; wherein the angles of the suction opening and the ejecting opening are arranged at a slant to the axis of rotation such that the suction opening is in an upward direction and the ejecting opening is in a downward direction, so that the suction flow is introduced diagonally downward from the up and the ejecting flow is ejected diagonally downward from the bottom of the suppressing body; wherein the suppressing body has an almost reverse truncated cone shape in which the diameter of the suppressing body becomes larger as going to an upper front end side of the suppressing body from a base end side of the suppressing body, the base end side contacting the stirring chamber, and wherein the upper front end side of the suppressing body extends upward beyond the suction opening. a stirring blade configured to rotate at a high speed and a stirring chamber provided with a screen enclosing the stirring blade, configured to perform, under a state in which the stirring chamber is disposed in a fluid to be processed, a process of applying a shear force to the fluid by rotating at least either one of the screen and the stirring blade thereby effecting a relative rotation between the screen and the stirring blade; the stirring chamber having a suction opening to suck the fluid from outside to inside and an ejecting opening to eject the fluid from inside to outside by the relative rotation, these openings being disposed at different axial positions along the axis of the relative rotation; characterized by a suppressing body connected to an outer wall of the stirring chamber between its suction opening and its ejecting opening, and extending outwardly from the stirring chamber so as to divide a suction flow, which is a flow of the fluid from outside into the suction opening, from an ejecting flow, which is a flow of the fluid ejected from the ejecting opening to the outside, thereby suppressing fluid interference outside the stirring chamber between the suction flow and the ejecting flow; wherein the angles of the suction opening and the ejecting opening are arranged at a slant to the axis of rotation such that the suction opening is in an upward direction and the ejecting opening is in a downward direction, so that the suction flow is introduced diagonally downward from the up and the ejecting flow is ejected diagonally downward from the bottom of the suppressing body; wherein the suppressing body has an almost reverse truncated cone shape in which the diameter of the suppressing body becomes larger as going to an upper front end side of the suppressing body from a base end side of the suppressing body, the base end side contacting the stirring chamber, and wherein the upper front end side of the suppressing body extends upward beyond the suction opening.