The magnetic particle spectrometer (MPS) uses the nonlinear response of super-paramagnetic iron oxide nanoparticles and magnetic saturation at certain magnetic field values. A time-varying magnetic field of excitation coils causes the magnetization of the particles to vary between the maximum and the minimum value. Generally, there are two ways in which a magnetic nanoparticle can change the direction when the applied area is temporarily changed. The particle itself performs a physical rotation called the Brown return, or the magnetic moment in the particle can rotate in a fixed structure called the Néel return. In a viscous environment, the combination of both types of rotation takes place, which depends on the frequency applied and is a dominant process. This process, also known as the relaxation meter, takes into account the density of the magnetic nanoparticles in the MPS studies and the measurement of the relaxation times of the nanoparticles by making the corresponding calculations. Brown or Néel breakdown times can be calculated according to the reaction of chemically bound or unbound magnetic nanoparticles to the external variable magnetic field. In this study, a spectrometer was first designed and constructed to analyze the properties of nanoparticles such as relaxation times. MPS signals obtained from the spectrometer can be transferred to the computer with data acquisition card and data analysis can be done with a software written in python programming language.