A semiconductor encapsulation material is used to fabricate a semiconductor device. The semiconductor device includes a semiconductor chip and an encapsulating portion. The encapsulating portion is made of a cured product of the semiconductor encapsulation material. The encapsulating portion encapsulates the semiconductor chip. A stress index (SI), given by the following Formula (1), of the semiconductor encapsulation material is equal to or more than 8500. If a volume of the semiconductor chip is represented by Vc and a total volume of the semiconductor chip and the encapsulating portion is represented by Va, the volume Vc and the total volume Va satisfy the following Formula (2). In Formula (1), E′ (T) represents a storage modulus, CTE (T) represents a coefficient of thermal expansion, and Mold temp. represents a molding temperature.







SI
=


∫

35
⁢
°
⁢


C
.



Mold
⁢


temp
.





[



E
′

(
T
)

×

CTE
⁡
(
T
)


]

⁢
dT






(
1
)













Vc
Va

≧

0.3
.





(
2
)