Recent theoretical and numerical studies on laser-driven ion acceleration shows sub- relativistic ion acceleration with multistep acceleration schemes. The multistep acceleration with multiple laser pulses and multiple targets allow us to access the relativistic ion regime with the current and the future laser facilities. However, there is no relativistic ion detectors available in the field of laser ion acceleration. We have been developing energetic ion diagnostics using a combination of solid state nuclear path tracker and Thomson parabola, and scintillator base relativistic ion detectors commonly used in nuclear physics. We introduce our recent progress on the laser driven ion acceleration and the novel diagnostics.日本物理学会2021年秋季大