  The paper studies several properties of Laplace hyperfunctions introduced by
H.~Komatsu in the one dimensional case and by the authors in the higher
dimensional cases from the viewpoint of \v{C}ech-Dolbeault cohomology theory,
which enables us, for example, to construct the Laplace transformation and its
inverse in a simple way. We also give some applications to a system of PDEs
with constant coefficients.
