The analogy between the difference equations of a wave‐equation boundary‐value problem and the current‐law equations of a direct‐current network is developed. This theory permits construction of a dc network analyzer for solution of the wave equation. Some of the network parameters are necessarily negative. These ``negative resistors'' are simulated by active dc circuits. The determination of characteristic frequencies, characteristic functions, and response to simple harmonic forces is illustrated by solution of an irregularly shaped membrane. Methods are discussed for solving problems involving inhomogeneous or anisotropic media or various types of boundary conditions.