安全工作区（英语：Safe operating area, SOA），是指功率半导体器件（例如双极性晶体管、场效应管、晶闸管以及绝缘栅双极晶体管）能够按照预期正常工作而不会造成损坏时的电压电流等条件的范围。

在半导体器件产品的手册或datasheet里，安全工作区通常以图像的形式标明，以晶体管为例，安全工作区标示图的横坐标是 V_CE（集电极-发射极电压）、纵坐标是 I_CE（集电极-发射极电流），而安全工作区的范围即为图中曲线与坐标轴所包围的区域。这一边界曲线中结合了器件的以下各项工作限制：最大电压、最大电流、与最大耗散电功率，而这些限制中也包含了对结的温度、内部热阻、晶粒焊线的载流能力和二次击穿这几项因素的考虑。

For power semiconductor devices (such as BJT, MOSFET, thyristor or IGBT), the safe operating area (SOA) is defined as the voltage and current conditions over which the device can be expected to operate without self-damage.

SOA is usually presented in transistor datasheets as a graph with V_CE (collector-emitter voltage) on the abscissa and I_CE (collector-emitter current) on the ordinate; the safe 'area' referring to the area under the curve. The SOA specification combines the various limitations of the device — maximum voltage, current, power, junction temperature, secondary breakdown — into one curve, allowing simplified design of protection circuitry.