The paper investigates a finite-dimensional servomechanism design for a parabolic distributed-parameter system with constant disturbances. The problem is to design a feedback controller such that the resulting closed-loop system will be exponentially stable and the controlled output will be regulated. With some assumptions with respect to a control operator and an output operator, the paper presents explicit sufficient conditions for the existence of a feedback controller which exponentially stabilizes and regulates the system. A finite-dimensional design procedure of a servomechanism is given and it is shown that the controlled output will converge to the constant reference vector with an arbitrarily assignable exponential decay rate. In the design procedure it is necessary to construct a finite-dimensional state observer in order to estimate the system state from observations.