The project proposed for a Master thesis within the laboratory of the Quantic group at BSC is based on advancing the coherent control of a superconducting qubit. The research group has the capability to cool down devices to a few millikelvin above absolute zero and generate the microwave signals necessary to the manipulation of the circuit's quantum state. The group also has several single qubit devices ready to be measured.Transmon qubits are at the forefront of solid state platforms for quantum computing. In this thesis, results obtained from the experimental study of a transmon qubit in a 3D cavity are presented. A complete view of the experiment is given, including cryogenic methods, microwave signal processing and spectroscopic and pulsed measurements of the transmon qubit. Lastly, partial results on state discrimination set the next step towards fully coherent control of the qubit