Microwave imaging device and method are provided, and the microwave imaging device includes a scan circuit, a reception circuit and an image generator. The scan circuit transmits a plurality of electromagnetic waves in a plurality of scan bands toward a target object. The scan bands are respectively corresponding to a plurality of biological tissues in the target object. The reception circuit receives the electromagnetic waves passing through the target object, and generates a plurality of energy values according to the received electromagnetic waves. The image generator looks up a plurality of gray level look-up tables by using the energy values to generate a plurality of gray level values, and generates a detection image corresponding to the biological tissues according to the gray level values.一種微波成像裝置與方法，所述微波成像裝置包括掃描電路、接收電路與影像產生器。掃描電路朝向目標物發射出位在多個掃描頻段的多個電磁波。所述多個掃描頻段與目標物中的多個生物組織一對一對應。接收電路接收穿透目標物的電磁波，並依據所接收的電磁波產生多個能量值。影像產生器利用所述多個能量值查詢多個灰階對照表以產生多個灰階值，並依據所述多個灰階值產生對應所述多個生物組織的檢測影像。
