NOVELTY - A pi-electron conjugated system organic silane compound has preset structure.    USE - As electric material, as electroconductive material to devices such as organic thin film transistor material, solar cell, fuel cell and sensor.    ADVANTAGE - The crystal structure with stable pi electron conjugation system portion is obtained without destroying by introduction of aliphatic hydrocarbon. The organic silane compound of high crystallinity degree, stability and dense packing characteristic is obtained. The movement of the carrier is smoothly performed by favorable conduction between compounds molecule and high electroconductivity is achieved along molecular axis direction. The organic silane compound having high solubility in non-aqueous solvent is manufactured conveniently, and prevents physical peeling when formed as film.    DETAILED DESCRIPTION - A pi-electron conjugated system organic silane compound has a structure of formula (1):    A-B-C-SiX1X2X3 (1)    A = 1-30C monovalent aliphatic hydrocarbon optionally substituted by halogen;    B = oxygen atom or sulfur atom;    C = divalent organic group which shows pi-electron conjugation; and    X1-X3 = group which gives hydroxyl group by hydrolysis.    An INDEPENDENT CLAIM is included for manufacture of pi-electron conjugated system organic silane compound. The monovalent aliphatic hydrocarbon (A) is introduced through ether bond or thioether bond by Williamson reaction to pi electron conjugation property structure containing molecule of formula (III). Then, the silyl group is introduced by reaction with a compound of formula (IV) to obtain pi-electron conjugated system organic silane compound.    H-C-H (III)    X4-SiX1X2X3 (IV)    C = divalent organic group having pi electron conjugation.    X1-X3 = same as defined above; and    X4 = H, halogen atom or lower alkoxy group.    DESCRIPTION OF DRAWING(S) - The figure shows the outline block diagram of organic thin film transistor produced using the organic silane compound.    silicon substrate (10)    organic semiconductor layer (12)    source electrode (13)    drain electrode (14)    gate electrode (15)