DIAGNOSTIC DEVICE

To make a precise diagnosis of a sign of abnormalities in an apparatus equipped in a vehicle.SOLUTION: A diagnostic device 10 includes: a detected-value acquisition unit 110 for acquiring the detected value of a first apparatus 30 equipped in first vehicles 1-2 and 1-3; an appropriate-value estimation unit 120 for estimating an appropriate value of the detected value of the second apparatus 30 in a second vehicle 1-1, using the detected value of the first apparatus 30; and a diagnosis unit 130 for comparing the detected value of the second apparatus 30 and the appropriate value of the detected value of the second apparatus 30 and diagnosing the operational state of the second apparatus 30. The first vehicles 1-2 and 1-3 are located within a predetermined range from the second vehicle 1-1, and the predetermined range is set according to the speed of the second vehicle 1-1 when moving.SELECTED DRAWING: Figure 2 【課題】車両に搭載された機器の異常予兆の診断を精度良く行う。【解決手段】診断装置１０は、第１車両１−２，１−３に搭載された第１機器３０の検出値を取得する検出値取得部１１０と、第１機器３０の検出値を用いて、第２車両１−１に搭載された第２機器３０の検出値の妥当値を推定する妥当値推定部１２０と、第２機器３０の検出値、及び第２機器３０の検出値の妥当値を比較することにより、第２機器３０の動作状態を診断する診断部１３０と、を備え、第１車両１−２，１−３は、第２車両１−１から所定の範囲内に存在する車両であり、所定の範囲を、第２車両１−１の移動速度に応じて設定する、診断装置。【選択図】図２