Disclosed are an X-ray transmission inspection apparatus and an inspection method using the same that are capable of preventing over-detection and erroneous detection of foreign matter even when variations in vertical position of the sample occur. The X-ray transmission inspection apparatus includes: an X-ray source (2) irradiating a sample with X-rays; a sample moving device (3) moving the sample S continuously to a predetermined direction while X-rays X are emitted from the X-ray source; a time delay integration sensor (TDI sensor) (4) provided opposed to the X-ray source based on the sample, and detecting the X-rays transmitted through the sample; a distance sensor (5) measuring a distance between the X-ray source and the sample; and a TDI controller (6) controlling the TDI sensor by changing a charge transfer speed of the TDI sensor (4) in real time based on variations in the distance measured by the distance sensor.