Abstract: A housing for a single-pole circuit breaker is disclosed. The housing includes two current path regions, each region having a first section configured to receive an electromagnetic protection device, a second section configured to receive a thermal protection device, a third section configured to receive an arc extinguishing device, and a fourth section configured to receive an operating mechanism device. Each first section occupies a substantial part of the available internal width of the housing, and is disposed between the respective third and fourth sections. Each second section occupies about half the available internal width of the housing.