A laboratory simulation experiment of low-energy electron beam injection into the ionosphere is performed. Two kinds of waves are excited in VLF frequency range. One with a lower frequency is shown to be caused by an interaction between the beam with a finite cross section and a background plasma. The other with a higher frequency is shown to be caused by a current-driven ion turbulence due to an electron return current. These two kinds of VLF waves have been observed before in Japanese rocket experiments in the ionosphere. A retarding potential analyzer measurement revealed that the injected beam has a diameter twice as large as the cyclotron radius of beaming electrons. It is shown that the field intensity of the excited VLF waves drops off outside the measured beam column. A correlation measurement of the phase of the VLF wave shows that the phase velocity of the wave excited by the beam instability is equal to that of ion acoustic waves. A dispersion and wave vector measurement has shown that the current-driven ion turbulence is an ion cyclotron wave whose phase velocity is of the order of the ion acoustic wave velocity Cg.