To provide a vascular sap measurement sensor in which a flow channel that receives incoming flow of vascular sap is unlikely to be blocked by tissues of a plant. A vascular sap measurement sensor 1 includes: a trapping probe 20 for trapping vascular sap； and a support 10 that supports the trapping probe 20. A trapping flow channel 21 that receives incoming flow of the vascular sap is formed in the trapping probe 20. The trapping flow channel 21 has an inlet opening 24 formed on a side surface of the trapping probe 20. This makes it unlikely that the trapping flow channel 21 will be blocked by tissues of a plant when sticking the trapping probe 20 into the plant.
