  We study a gate-tunable superconducting qubit (gatemon) based on a thin
InAs-Al hybrid nanowire. Using a gate voltage to control its Josephson energy,
the gatemon can reach the strong coupling regime to a microwave cavity. In the
dispersive regime, we extract the energy relaxation time $T_1\sim$0.56 $\mu$s
and the dephasing time $T_2^* \sim$0.38 $\mu$s. Since thin InAs-Al nanowires
can have fewer or single sub-band occupation and recent transport experiment
shows the existence of nearly quantized zero-bias conductance peaks, our result
holds relevancy for detecting Majorana zero modes in thin InAs-Al nanowires
using circuit quantum electrodynamics.
