The goal of this master’s thesis is a development of precision modular dual head vector AMR magnetometer. Main ideas and principles, circuit and mechanical diagrams, PCB and firmware design are presented as well as notes on assembly, debugging and testing. Modularity is based on dividing the magnetometer in two main parts: sensor heads and control and evaluation electronic. Part of this thesis is also perform testing measurements, determinate key parameters and compare them with values listed in the available literature. Influence of different types of compensation coils and replaceability of the obsolete sensor are also evaluated.