Dry toilet device comprising: - a rigid bowl having a seat, - at least one concave part intended to receive stools, - at least one rotation arm on which a scraper for evacuating the stools is fixed, the rotation arm pivoting so as to move the evacuation scraper over the concave part in a descending direction between two positions in order to evacuate the stools from the concave part into a lower opening, - an actuating means connected to the rotation arm so as to pivot the rotation arm under the action of the user, - return means that are connected to the rotation arm and return the rotation arm, characterized in that: - the bowl has the concave part that is intended to receive the stools, the concave part being in the form of a circular arc, - the rotation arm pivots so as to move the evacuation scraper over the concave part between an initial top position and a bottom position, - the evacuation scraper is arranged to have a deformation or displacement of a lower end with respect to the part that is in the form of a circular arc, said deformation or displacement being different in the rising direction than in the descending direction, so as to obtain a scraping force on the part of the rigid bowl that is in the form of a circular arc that is greater in the descending direction towards the bottom position than the reduced or zero scraping force that is obtained in the rising direction towards the initial top position, - the actuating means is connected to the rotation arm in order to pivot the rotation arm, under the action of the user, in the descending direction from the initial top position to the bottom position, and - the return means enable to return the rotation arm to its initial top position in which the evacuation scraper is supported in the bowl. - a rigid bowl having a seat, - at least one concave part intended to receive stools, - at least one rotation arm on which a scraper for evacuating the stools is fixed, the rotation arm pivoting so as to move the evacuation scraper over the concave part in a descending direction between two positions in order to evacuate the stools from the concave part into a lower opening, - an actuating means connected to the rotation arm so as to pivot the rotation arm under the action of the user, - return means that are connected to the rotation arm and return the rotation arm, - the bowl has the concave part that is intended to receive the stools, the concave part being in the form of a circular arc, - the rotation arm pivots so as to move the evacuation scraper over the concave part between an initial top position and a bottom position, - the evacuation scraper is arranged to have a deformation or displacement of a lower end with respect to the part that is in the form of a circular arc, said deformation or displacement being different in the rising direction than in the descending direction, so as to obtain a scraping force on the part of the rigid bowl that is in the form of a circular arc that is greater in the descending direction towards the bottom position than the reduced or zero scraping force that is obtained in the rising direction towards the initial top position, - the actuating means is connected to the rotation arm in order to pivot the rotation arm, under the action of the user, in the descending direction from the initial top position to the bottom position, and - the return means enable to return the rotation arm to its initial top position in which the evacuation scraper is supported in the bowl.