A collecting device for loosening and collecting debris in a well comprises a first and second end portions, a collecting receptacle between the first and second end portions having at least one receptacle section and at least one screen receptacle, and a motor. The device at its first end includes a feed pipe, a conveying screw in feed pipe driven by the motor and arranged to move the debris in towards the collecting receptacle, and a tool at the leading end portion of the conveying screw. A method described of loosening and collecting debris in a well by the collecting device.