This paper deals with a design method for the buck type switching regulator satisfying the transient and steady state performances. Necessary design considerations on the power stage are given, before designing the controller, to obtain a better closed-loop transient responses with less control effort under the constraint of the permissible switching ripple, and a feedforward compensation is also given to effectively improve the steady state performances. In the design of the controller, a PIM (proportional-integral-measurable) control method with optimized constant feedback gains is proposed to obtain better dynamic performances in the time domain without complicating the implementation of the controller. On the optimization of the controller parameters, two different design techniques, such as; 1) a method using the time weighted quadratic performance index and 2) a method using the explicit model following concept, are presented respectively. The usefulness of the proposed design method which includes the design of the controller as well as the power stage is proved by the computer simulations and experimental results for design examples.