AbstractStationary excitation of plasma oscillations by an external alternating electric field in a collisionless onedimensional plasma layer (plasma condenser) is examined. For this the linearized onedimensional Vlasov equation is integrated along the one‐electron characteristics, assuming the electrons are reflected specularly at the boundaries. In the case of a homogeneous plasma the resulting Fredholm integral equation for the electric field is solved exactly. The results agree with Shure's, received on the basis of distributional analysis à la Van Kampen and Case. In view of Tonks‐Dattner resonances the resonance properties of the homogeneous plasma condenser are discussed. Contrary to the hydrodynamical theory here we receive only a finite number of resonances, increasing with the ratiorof layer diameter to Debye length. The ratio of series limit to main resonance position is nearly constant forrnot too small. This agrees with Dattner's qualitative statements about Tonks‐Dattner resonances found experimentally. However, the kinetical effect of series limit and another one of a second serie of resonances at lower frequencies are masked by strong Landau damping in this region of dispersion. The method of characteristics used here has the advantage of easily being generalized for the case of an inhomogeneous plasma condenser. For this case an integral equation for the electric field is derived in full analogy to the procedure employed for the homogeneous plasma. Finally the kernel of this equation is specialized for a parabolic static pot