A method of producing a sheet type laundry detergent which comprises continuously or discontinuously applying a doughy detergent composition that has been prepared so as to have a viscosity of 1,000 mPas to 50,000 mPas at a shear rate of 10 s.sup.-1 to 1,000 s.sup.-1 onto a flexible support of continuous length that is running continuously in a prescribed direction under a shear rate condition of 10 s.sup.-1 to 1,000 s.sup.-1 by an application to form a thin layer of the doughy detergent composition.