This thesis is an experimental study of the nuclear force. In the first part of the thesis the single particle structure of 208Bi is studied via the γ - γ coincidence technique. This experimental data provides information about the residual particle-hole interaction in the Lead region. In the second part of the thesis the structure of 7He is studied. The experimental study of 7He was motivated by experimental evidence for reduction of the spin-orbit force in the above nucleus. To study the 7He structure two new experimental techniques were developed. The new data obtained with these techniques showed that there is no reduction of the spin orbit force in 7He. It is shown that the developed methods can be used to study other exotic neutron rich nuclei. The techniques are described in details in this work and future prospectives are given.