We study the stationary scattering theory for a perturbed $1$-body Stark operator. We prove existence and completeness of the stationary wave operators, construct the associated generalized Fourier transforms, and characterize asymptotics of the generalized eigenfunctions of minimal growths in terms of the stationary scattering matrix. A key element of our procedure is an improved (possibly optimal) version of radiation condition bounds obtained previously, which in turn is proved by a new scheme of proof.